Ruby: Workaround for optimiser problem.

A size 1 DataFlowType causes misoptimisations.

Author: aschackmull

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowPrivate.qll

@@ -710,14 +710,16 @@ predicate clearsContent(Node n, Content c) {
   FlowSummaryImpl::Private::Steps::summaryClearsContent(n, c)
 }
 
-private newtype TDataFlowType = TTodoDataFlowType()
+private newtype TDataFlowType =
+  TTodoDataFlowType() or
+  TTodoDataFlowType2()
 
 class DataFlowType extends TDataFlowType {
   string toString() { result = "" }
 }
 
 /** Gets the type of `n` used for type pruning. */
-DataFlowType getNodeType(NodeImpl n) { any() }
+DataFlowType getNodeType(NodeImpl n) { result = TTodoDataFlowType() and exists(n) }
 
 /** Gets a string representation of a `DataFlowType`. */
 string ppReprType(DataFlowType t) { result = t.toString() }